常

Why does 常 look like this?

Top: 尚 (shàng - high/ancient), which provides the sound 'chang' in ancient phonology. Bottom: 巾 (jīn - cloth/towel). Historically, 'chang' referred to a standard length of cloth used for banners, which led to the meaning of a 'standard' or something that is 'always' there. Think of it as a flag that stays up constantly!